Melting of scalar mesons and black-hole quasinormal modes in a holographic QCD model

Understand

A holographic model for QCD is employed to investigate the effects of the gluon condensate on the spectrum and melting of scalar mesons.

• We find the evolution of the free energy density with the temperature, and the result shows that the temperature of the confinement/deconfinement transition is sensitive to the gluon-condensate parameter.
• The spectral functions (SPFs) are also obtained and show a series of peaks in the low-temperature regime, indicating the presence of quasiparticle states associated to the mesons, while the number of peaks decreases with the increment of the temperature, characterizing the quasiparticle melting.
• In the dual gravitational description, the scalar mesons are identified with the black-hole quasinormal modes (QNMs).